In the diagram, you can see the 3Ps that are common to most early 21st century views of online or virtual communities – People (membership), Policies (governance), and Purpose (individual and/or group attribute).

The aspect (that is Steinmueller’s contribution) that seems particularly relevant to me is Sustainability. Steinmueller characterised this as something that is lost

either when the costs of participation exceed the willingness to participate

or there is a coordination failure .

The coordination failure could be that horrible experience when you log in one morning to find that the space no longer exists, or something else goes wrong.